1. Field of the Invention
The present invention relates to a fuel injection system for injecting fuel into an internal combustion engine and more particularly to a fuel injection system for electronically controlling the amount of fuel injection or the injection quantity.
2. Description of the Prior Art
A conventional system of this type supplies low-pressure fuel to an electromagnetic fuel injector by means of a low-pressure fuel supply device. The only function of the injector is to open/close a nozzle, and, hence, it serves to inject the low-pressure fuel. Since the injection quantity is controlled in accordance with the valve opening time, one injection operation is performed per rotation of the engine.
Since the conventional fuel injection system has the structure described above, there is a problem in that it cannot inject high-pressure fuel.
For this reason, in the case of high-pressure injection, a combination of an injection pump of the plunger type, a long injection pipe, and an automatic valve has usually been used, and, accordingly, essential electrical control has not been realized because of the difficulties of such essential electrical control.